Evolvulus nummularius (L.) L. (Convolvulaceae): a new alien plant record for Pakistan

Evolvulus nummularius (L.) L., a member of the Convolvulaceae, is native to Mexico and South America but nowadays grows around the world in many tropical and subtropical regions. Its presence in Pakistan, where it has become naturalized, is reported here for the first time. It was first discovered in Pakistan in the Jhok Reserve Forest in Lahore city of Punjab Province on September 5, 2016. It has since been found in four more localities in Lahore. Although E. nummularius has some medicinal value and is edible, it is usually considered a weed in the south and southeast of Asia. A detailed morphological description and comparison with other species is provided together with illustrations and an identification key for the two species of Evolvulus now established in Pakistan. In addition, the geographic distribution, ecology, economic importance, and invasive potential of E. nummularius are discussed. The description and key have been integrated with other floristic resources for Pakistan via two web sites, OpenHerbarium and KeyBase, to facilitate their discovery. Eradication of this introduced herb is probably impossible, but steps can and should be taken now to restrict its further spread within Pakistan before it affects the productivity of croplands.